/*
 * acm1216.c
 *
 *  Created on: 20 Mar 2010
 *      Author: xuxu
 */
#include<stdio.h>
int main()
{
	double over;
	int n;
	int i;
	printf("# Cards  Overhang\n");
	while(scanf("%d",&n)!=EOF)
	{
		over=0.5;
		for(i=2;i<=n;i++)
		{
			over+=(double)1/(double)(i*2);
		}
		printf("%5d     %.3lf\n",n,over);
	}
	return 0;
}
